Coupling device



July 6, 194s. E. M. MCELHINNEY 2,444,575

yCOUPLING DEVICE Filed Oct. l, 1945 2 sheets-sheet 1V July 6, 1948- E.M. MCELHINNEY 2,444,575

COUPLING DEVICE Filed Oct. 1, 1945 2 Sheets-Sheet 2 Patented July 6,1.948

UNITED STATES PATENT OFFICE Eric M. McElhinney, Dysart, Iowa ApplicationOctober 1, 1945, SerialNa 619,561l

This invention relates generally vto coupling -devices and in particularto a coupling for connecting a trailer unit with a tractor unit.

It is an object of this invention to provide an improved couplingdevice.

A further object of this invention is to provide a coupling 'which iscapable of maintaining a trailer unit and a tractor unit in positiveconnection for all relatively moved positions of the two'units.

Yet another object of this invention is to provide a coupling which iscontinuously self-locking regardless of any wear which might occur inits locking mechanism.

Another object of this invention is to provide a coupling in which apivoted latch, in a hitch locking position, is positively but releasablyheld against pivoted movement by any forces acting 1 on the hitch.

A further object of this invention is to provide a coupling which issimple and rugged in construction, comprised of a minimum number ofmovable parts, positive inr operation, and easily and quickly operatedto locking and releasing positions.

A feature of this invention is found in the provision of a couplingdevice for a tractor unit and a trailer unit in which a coupling memberon a iirst one of the units. is of a construction to releasablypivotally support a hitch for. up and down pivotal movement. The hitchin turn is plvotally connected for relative lateral movement with arotary member, which is rotatably supported on the second one of theunits for rotation about an axis extended substantially longitudinallyof the coupling member on the first unit, whereby the two units arepositively con- I nected in all relatively moved positions.

Another feature of this invention is found in the provision of acoupling Idevice which has a body member with a transverse grooveadjacent one end, an upright support on one side, land a latch pivotedat one end on the support at a position spaced from the body member. Thelatch is provided with a hookv at its opposite end adapted to close, inmating relation with the transverse groove, concurrently with thelocation of its free end across the one end of the body member. A hitch,including a pair of transverselongitudinally spaced members. ispositionable on the body member with one transverse member in the bodymember` groove, and the second transverse member adjacent to thesupport. On movement of the latch to its hitch closing position, thelatch moves against the second trans- .Of the hitch;Y

verse member,'concurrently ywith the hookflocking the Iirst transverse,memberl inthe body'inem-v hitch is lockedin a iixed` ber groove,so'that. the position on the body member. V

A further feature of thisjinvention found in theprovisionof a couplinghaving a body memberl'formed with a transverse groove adjacentone end topartially receive a portion of'a hitch. A tension actuated latch pivotedonthe, body member isr movable to a tended 'outwardly fromfthe bodymember,I and has ahook at its freeend adapted, onmovement ofvvthelatchtoa second position, to form with Another feature-otthis,invention found in the provision of a coupling having la flat bodymember with a transverse groovein one sidelor partially receiving aportion' ofia hitch, sothat'` the hitchis removable from the groove onthe:y application of a pullingforce on the'hitch'. A? pivoted latch isvpivotally supportedv on thebody member and `has a portion movable into aco` acting position with the groove 'to lock the hitch againstY removaltension actuated holdthe latclfi fa' hitchlocking' position.` f

Further this rinvention will become lowing description when taken inconnection the accompanying drawings 4in which:A i

Fig. 1 is aside4 elevational View `ofwthe coupling from the bodyjmember,with -a with device ofethis invention shownsinjafcoupled pos'i-` y tion;and withcertain parts broken `away to more clearly show itsconstruction;I 4

Fig. 2 isa plan view of the'coupling shownin Fig. 3`isamdetailsectional. View asseen onthe line 3 3 'in Fig. 2;

` Fig. 4 is aperspectivevew of theeouplingwltn parts broken away,showing the hitch out of. its coupled position, but adapted to be movedto,-a-

coupled. position byl/the v.application of force thereon; y

Fig. 5 isy al prsp a; lllling Fig. Slis a side elevational vieviT of thecoupling first position' exapplication of 'a pulllocking meansbeingprovided to gainst pivotal movement in :its

objects', features and advantagesof Q apparent from the fol-v efiiieView ,0f amedied for@ of this invention shown in coupled relation withthe hitch shown in Fig. 5; and

Fig. 7 is a fragmentary plan view of the coupling shown in Fig. 6, withcertain portions broken away to more clearly show the assembly thereinof the modified form of the hitch shown in Fig. 5.

Referring to the drawings the coupling of this invention is shown inFigs. l, 2 and 4 as including a coupler unit having a flat body memberI0 with a transversely extended groove II, of an arcuate shape, adjacentits end I2. The body member I6 is illustrated in Figs. 1 and 2 as beingsupported on a longitudinally extended or swinging type drawbar I3 for atractor (not shown), and connected to the drawbar by bolts I4. It isapparent, of course, that the free end of the drawbar may constitute thebody member I0. The groove II is of a shape and size adapted topartially receive an end member I6 of a hitch, indicated generally asl1, so that the hitch member I6 is readily removable from the groove I Ion the application of a pulling force on the hitch.

In order to lock the hitch I1 against movement from the groove I I,while pivotally supporting the hitch at the groove for pivotal up anddown movement, there is provided a pivoted latch I8 having one endpivoted at I9 between a pair of transversely spaced supports 2l extendedupwardly from the top side of the body member I0. AsA clearly appearsfrom Figs. l and 4, the pivot I9, for the latch I8, is at a positionspaced upwardly :from the top side of the body member I0, so that thelatch, in a hitch locking positionk is inclineddownwardly from its pivotI9 toward the body member end I2. A space 28 is thus provided between-the pivoted end of the latch I8 and the body member ID for a purposewhich will appearlater.

A hook or laterally bent member 22 at the free end of the latch I8(IFig. 4) is formed with a recess 23 for receiving a lug or ear 24extended longitudinally from the-body member end I2, when the latchapproaches and is ina hitch locking position.r .The inner wall of thefree end -of the hook 22 is formed with a shoulder 26 and a transverselyextended groove 21 (Fig. 3). When the latch is in a hitch lockingposition the free end of the hook 22 extends over and across the end I2kof thebody member IU, the grooves 21 and II inthe Whook and body member,respectively, are oppositely arranged and in a mating relation so as toform a closed annular bearing forpivotally supporting the hitch memberI6, and the shoulder 26 is arranged oppositely from a lip portion 25 onthe body member I0, located between the groove II and the end I2 of thebody member.

The lip .25 and shoulder 26 are normally spaced apart from each other toprovide for the grooves I I vand 21, in their mating relation,accommodating small diameter variations in the hitch member I6. Also inthe vevent of any wear in the transverse grooves II and 21 a sidewall ofthe groove Il adjacent to the end I2 of the Ibodi7 member will bemaintained over long periods of use of the coupling. The lip 25 andshoulder 26 valso cooperate to provide a full bearing surface for thehitch member I6 within the annular support formed Iby the grooves II and21 in mating relation. j

The hitch I1 (Figs. 2 and 4) is of a flat form and a substantiallytrapezoidal shape and has an opening Y29 'donned by the end member I6, aflat end member 3l and side members .32. The

flat end 3l is receivable in a clevis 33 and is pivotally connected withthe clevis by a bolt 34 extended through the clevis and an opening 36 inthe flat end 3i. The clevis 33 is provided at its closed end 35 with alongitudinally extended shaft 31 rwhich is rotatably supported in abearing unit comprised of a bearing sleeve 38 having oppositely arrangedside plates 39 welded thereto. The clevis 33 is held against axialmovement relative to the sleeve 38 by its closed end 35 and by a nut `42which is threadableon the free end of the shaft 31 for contactengagement with the sleeve 38 and supporting plates 39. The bearing unitis initially assembled with the shaft 31 and the clevis l33, and is thenpositioned between a pair of supporting plates 43 provided on a tongue45 or the like for a trailer unit (not shown) The plate members 39 aresecured to the plate members 43 by bolts 44.

It is seen, therefore, that when the hitch I1 is in its locked positionWith the body member IIJ it is pivotally movable in an up and downdirection about its end I6 which is held against movement transverselyof the body member I0 by the stop action of the hitch sides 32 with thehook 22. Relative transverse movement between the two connected units ispermitted by the -pivotal connection of the hitch with the clevis 33 atthe pivot 34, while transverse tipping movement between the twoconnected units is accommodated by the rotatable support of the clevisshaft 31 on the trailer unit.

rihe hitch I1, as best appears in Figs. 2 and 4 is Widest at its at end3I and tapers or converges toWard the end member I6, so that the sidemembers `32 are inclined toward each at the end member I6. It is thusseen that the opening 29 is of a trapezoidal shape having its widestside at the fiat hitch end 3l. This construction of the hitch Ilprovides for the end member I6 being initially positionable on the bodymember I0 and out of the groove II when the tractor unit and Ythetrailer unit are offset from each other, that is out of longitudinalalignment, and for the movement of the end member I6 within the groovesII and 21 when the tractor unit is later operated in a forwarddirection, as will be later fully explained. The opening 29 is of a sizeto loosely receive the hook 22 but with the hook being adapted forcontact engagement with the hitch side members 32 when the hitch is in alocked position, to limit transverse movement of the hitch relative tothe body member I9.

The latch 'I8 is positively locked in a closing position relative to thegroove 1I, in the body member I9, by means including a pivoted lockingmember 41 pivotally supported at 48 between the upright supports 2I. Asshown in Fig. 1 the pivot 48 is spa-ced upwardly. from' and tol one sideof the pivot I9 for the latch I3. The locking member 41 is o asubstantially bar shape and on pivotal movement in a counter-clockwisedirection, from the dotted line position shown in Fig. l, is movalble toa latch locking position superposed on'thej latch I8 and with its freeend 49 engageable with an upstanding projection 5I formed on the topside of the latch I8.

With the latch I8 and the locking member 4l in their relative superposedpositionslshown in Fig. 1), and with the hitch end I6 locked Within thegrooves Iil and 21 any for-ce tending to move the latch in a clockwisedirection, away from a hitch locking position is transmitted through thelatch projection 5I to the locking member 41 and longitudinally of thelocking member 41 to its pivotal support 48. This force is-thus directedthrough the axial center of the pivotal support 28 so that'there is nomoment arm of the locking member 41 about its pivotal support or axis48.

The locking member 41 is lconnected with the latch It through a lostmotion mechanism comprising an inverted U-shaped member 52 arranged in astraddled relation with the locking member 41 and having its free endssecured to the top side of the latch I8. A manual grip 53 is ex' tendedupwardly from the free end lof the lock 41. Thus to move the latch I8out of its hitch locking position the handle 53 is gripped and thelocking member 41'is initially moved in a clockwise direction, as viewedin Fig. 1, .toward its dotted line position, also shown in Fig. 1, untilits free end 49 is out of an engaging position with the latch projectionI. At this time the U member 52 is engaged by the locking member 41 andthe latch and locking member are then simultaneously moved to theirdotted line positions shown in Fig. 1.

It is seen, therefore, that with the locking member 41 and the latch I8supportedvon pivots off set from each other, a relative longitudinalmovement between these kparts takes place concurrently with theirpivotal movement through different arcuate paths by means of their lostmotion connection 'through the U member 52. The lost motion connectionthus provides for a predetermined relative movement of the latch andlocking member .to their respective hitch holding and latch lockingpositions, and for the lifting of the locking member 41 out of a latchlocking position prior to the movement of the latch from a hitchlocking' position, all in response to the manipulation of the lockingmember 41 in reverse directions.

The locking member 41 is yieldably held in a latch locking position withthe 'projection 5| by a pair of tension springs 51 arranged at oppositesides of the supports 2I. Each vspring 51 is connected at one end to thepivot 48 for the locking member 41 and at its opposite end to a lateralextension 58 at the free end 48 of the locking member t1. As seen inFig. 1 the pressure of the springs 51, when the locking member 41 is in-a latch locking position, is applied in a substantialn ly horizontalyplane and below the pivot 48 so that the free end i9 lof the lockingmember 41 is continuously urged into engagement with the projection 5Ion the latch I8. Itis apparent, therefore, that the springs 51 areentirely free of any forces tending to move the latch I8 away from ahitch locking position, since such forces are ap- Dlied through thelocking member 41 to its pivotal support 48. On movement of the lockingmember and latch to their relative positions shown in dotted lines inFig. l, the longitudinal axes of the springs 51 are moved upwardlythrough the pivotal support d8 so that the force of the springs isapplied in a substantially upright plane and to the right of the support48 to yieldably hold the latch and locking member away from a hitchlocking position. rlhe springs 51 thus function to alternately yieldablyhold the locking member 41 in a latch locking position, and the lockingmember lll' land the latch I8 out of a latch locking position and ahitch locking position, respectively.

When 4the longitudinal axis of the end member i6 of the hitch I1 issubstantially parallel to the transverse groove III it is apparent thatthe meme ber will be readily received within the' groove Il.In'order`-that the hitch I1l can befinitiallyf-con neoted when a sidemember 32 is in a parallel relationwith the groove,"or when theendmember I6 is inclined transversely in a-supported position on thebody member .10, the side mem-bers 32 are inclined inwardly..l toward...theiend mem ber I4, as was .explained above, and of a size incapableof being individually received withinthe. grooveII.

Thus with the latch I=8 in its dotted line lposition shown in Fig. 1 thehitch I1 ispositionable anywhere on the body member I 0 between theupright supportsfZLand. the end I2. of the body member II'IA and withtheend member IIY out'of a parallel relation with .the transverse. grooveII. The latch vI3 is ireleasedfrom its dotted-line po.- sition shown inliigzll and permitted to be yield.l ably urged A`againstvthe top of thehitch `I1 4by the action of the ysprings Blas-shownin Fig. 4. At this`position of the hitch the hook 22 extends partially across the endI2.of. the bodywmember I0 and .within the hitch opening 29,.and.the lug24 is partially received within the recess-5.23. in 4the hook 22.'`Inother words, the=spafce 28between. the body memberY and `the-latch. I8isof a height to snug-ly receivea side ..orlendqmember. of l.the hitchI1 therein, concurrently with, the location of .the hook 22 relative `tothe bodymember .Ill as above explained. l

On a forward vmovement `of `the tractor, ,ory onv movement ofthe bodymember IUto therigh'has. viewedin Fig. 4, the, slanted arrangementoftheside members 32 provides for apivotal movement of the hitch I1 relativeto thehook 22 yuntil the. endmemberldtis inra substantiallyparallelrela.- tion with, the transverse groove I I. When .this occurs the endmember I6 ismoved toits position within the grooves II and 21concurrentlyfwith the movement of xthe latch I8 toits hitchlockingposition,` and the locking member 41 1:0 its latch locking position inresponse to the actionA of ther springs .51. vAs a result, even.thoughthe tractor and trailer may be. out of. longitudinal alignmentwhen initially connected, thev twounits. are positively .andautomatically connected assoonas the tractor .is moved forwardly. Inorder tore. leasey the. .hitchlI1 the :locking member 41 .and latch l8are moved to their dotted linelpositions shown in Fig. 1, soth'at thehook 22 is clear. of` the body member I Il. By virtue of thefpartialreception of the hitch end member I6 within the groove II, the hitch isdisconnected fromthe body member Il) on the application of a pullingforce thereon. In one embodiment ofthe inven-, tion the vgroove vII Ahasa depth of el@ inch `and the end member I6 a diameter of %,inch. Thelargest portionv of the end member IE is thus received within the'latchgroove 21, while the groove II `is incapable of holding'the end mem. berI 6 for a substantially longitudinal pull.

In some instances of operation, such as-in the pulling of a two wheeltrailer, in which the tongue is supported on the tractor unit, the useof aV hitch which is pivotally movable in an up and down direction i-sobjectionable. However, this objection is eliminated by the provisioncfa mod-A ified form of hitch shown inFigs. 5, 6 and 7 and adapted forconnection with the coupling shownlongitudinal members 66 connected attheir free ends by an end bar or member 61 and intermediate their endsby a second bar or transverse member 68. The opening l between the side68 ofthe flat end 6I and the transverse bar 68 is of a size to looselyreceive the hook 22 of the latch I8, while the distance between the bars61 and 68 provides for the end bar 6l being adjacent to the uprightsupports 2I when the second bar 68 is received within the transversegrooves II and 21.

Thus as shown in Figs. 6 and 7, when the hitch I1 is positioned on thebody member Ill, and the latch' I8 is in its hitch locking position, theside members 66 are arranged at oppositie sides of-the body member I0between its end I2 and the supports 2l, concurrently with the locationof the transverse bar 68 within the groovesk II and 21, and the locationof the end transverse bar 6l' in contact engagement with the bottom sideof the latch I8, the top side of the body member I0 and one side of th'esupports 2l. Since the latch I8 is positively held against pivotalmovement in a clockwise direction, as viewed in Fig. 7, by the locking`action of the locking member 4l, the hitch II' is positively held in afixed position relative to the body member ID. As a result any pivotalmovement of the hitch I1' is positively eliminated, and the hitchfunctions as an extension of th'e body member IIJ to support any trailerunit connected therewith at its at end 6 I In the event the coupling isto be connected to a plow or the like the hitch I1' may be formed with aloop portion connecting the sides 66 in place of the flat end BI, andachain or the like extended through the loop for connection with thehitch I1.

Athough the hitches Il and I1' have been described -as being on atrailer unit and the body memberv Ill on a tractor unit, it is to beunderstood that these parts can be relatively used on either unit. It isto be understood also th'at although only a preferred embodiment of theinventionhas been illustrated and described herein the invention is notto be so limited, since modiiications and changes can be made thereinwhich are within the full intended scope of the invention as dened inthe appended claims.

I claim: l

Y1. .A coupling device for a tractor unit and a trailer unit including aflat body member carried on one of said units and having a transverselyextended arcuate groove adjacent one end thereof for receiving a portionof a hitch carried on the other of said units, an upright support onsaid body member, a projection extended longitudinally from said one endof the body member, a pivoted latch pivotally supported at one end onsaid upright support at a position spaced from said body member, andhaving a lateral projection at its other end movable across the one endof said body member, with said lateral projection having a recesstherein adaptedto receive said longitudinal projection onsaid bodymember, when the latch is in. one of its pivotally moved positions, saidother end of the latch having `a transversely extended annular groovespaced inwardly from said projection, with said two grooves, when saidlatch is in said one position, being in mating relation to form anannular support for said hitch portion to lock said hitch portiontherebetween, with `said latch in a second moved position being in aSubstantially uprightposition .whereby to release said hitch portionbetween said two grooves, and means for releasably locking said latch insaid one position, said latch in said one position being inclinedrelative to said body member to provide for the hitch portion beinginitially positionable on said body member between said body membergroove and said upright support and movable into said body member grooveon the application of a pulling force between said two units.

2. A coupling device for a trailer unit and a tractor unit comprised ofa flat body member adapted to have -one end supported on one of saidunits, said body member having a transverse groove adjacent the oppositeend thereof adapted to receive a portion of a hitch carried on the otherof said units so that said hitch portion is removable from said grooveon the application of apulling force between said two units, aprojection extended longitudinally from said opposite end of the bodymember, an upright support on said body member, a pivoted latch forlocking said hitch portion in said groove pivotally supported at one endon said support at a position spaced from said body member, said latchbeing pivotally movable in one direction to a hitch locking position,and in an opposite direction to a substantially upright position, alaterally extended portion at the free end of said latch movable acrossthe opposite end of said body member and having a recess therein adaptedto receive said end projection on the body member, with said latchhaving a transverse groove therein adjacent to said lateral portion forreceiving said hitch portion when the latch is in its hitch lockingposition, means including tension means for moving and releasablylocking said latch in said hitch locking position, said hitch portion,when the latch is in said substantially upright position, beingpositionable on that part of the body member between its opposite endand said upright support and, when said latch is moved into engagementtherewith, being movable to a locked position between said twotransverse grooves on an application of a pulling force between said twounits.

3. A coupling device for a tractor unit and a trailer unit comprised ofa at body member having one end adapted for support on one of said unitsand a transverse groove in its top side adjacent its opposite end forreceiving a portion of a hitch .carried on the other of said units, saidgroove being of a depth such that said hitch portion is removabletherefrom on the application of a pulling force between said tivo units,a pivoted latch pvotally supported at one end at a position spacedupwardly from the top side of said body member for pivotal movement to a`rst position ior locking said hitch portion in said groove, and t0 asecond position extended upwardly from said body member top side, withthe latch, in said first position, being inclined downwardly from itsone end toward said opposite end of the body member, a hook at the otherend of said latch having its free end portion movable across saidopposite end of the body member, said hook free end portion being of alength such-that it is positioned at said opposite end of the bodymember when the hitch is located out of said groove and between thelatch and said body member, and means including tension means for movingand releasably locking said latch in said rst position, with said hitchportion, in a position on said body member and out of said groove, andwith said latch in a released position on the top thereof, being movableto a locked position within said groove and said hook on the applicationof a pulling force between said two units.

4. A coupling device for a tractor unit and a trailer unit including abody member adapted to be supported at one end on one of said units andhaving a transverse groove in one side adjacent its opposite end, anupright support on the one side of said body member, a pivoted latchpivotally supported at one end on said support at a position spacedupwardly from said body member one side, and having a hook at its freeend movable into and out of a mating position with said transversegroove and forming with said groove an annular bearing support, with thefree end of the hook, in said mating position being extended across theopposite end of said body member, and the pivoted end of the latch, atsaid mating position iof the hook, being spaced upwardly from the oneside of said body member, a one piece hitch having a portion connectiblewith the other of said units, a pair of transversely spaced membersextended longitudinally from said hitch portion, a rst transverse memberconnected between the free ends of said longitudinal members, and asecond transverse ERIC M. MCELHINNEY. REFERENCES CITED The followingreferences are of record in the 'file of this patent:

UNITED STATES PATENTS Name Date Wixcel Sept. 23, 1913 Graham Nov. 29,1921 Bleoo Apr. 18, 1922 Mohr Nov. 17, 1931 Number

